ndspec

A crate for ocean waves with a specific focus on energy density spectra.

lib.rs:

ndspec

ndspec is a crate for working with energy density spectra with a focus on ocean waves, wind, and related response spectra.

The crate is organised into the following modules:

• core - Core functionality for working with energy density spectra.
• waves - Functions for calculating energy density spectra for ocean waves.
• wind - Functions for calculating energy density spectra for wind.
• spectrum - provides the Types Spectrum1 and 'Spectrum2' for one-dimensional and two-dimensional spectra respectively.

All wave and wind spectra can be converted into either a Spectrum1 or Spectrum2 Type. These types provide various traits for working with and evaluating energy density spectra.

The crate is designed to be used in conjunction with the ndarray crate. The ndarray::Array1 and ndarray::Array2 types are underlying data structures adopted throughout.

The crate also provides a Python extension that can be compiled and installed seperately.

Installation

Add the following to your Cargo.toml file:

[dependencies]
ndspec = "0.1.0"

Usage

The following example demonstrates how to calculate the energy density spectrum for a Bretschneider wave spectrum:

use ndspec::prelude::*;

let hs = 1.5;
let tp = 18.0;
let mut bretschneider = Bretschneider::new(hs, tp);
let omega = Array1::linspace(0.1, PI, 100);
let energy = bretschneider.set_omega(omega).energy();

Python Extension

The crate provides a Python extension that can be compiled and installed seperately. To build the extension, maturin is required and the python-extension feature must be enabled:

maturin build --release --features python-extension

and install with pip.

Examples

Define a Jonswap energy density spectrum from only Hs and Tp, convert to a Spectrum1D type, and then evaluate the most probable maximum amplitude over a 3 hour (10,800 s) time window:

import ndspec
S = ndspec.Jonswap(hs=1.5, tp=10.0).to_spec1d()
print(S.Ampm(10_800))

Print out the help for the Jonswap class in Python::

import ndspec
help(ndspec.Jonswap)

![energy density data structure][label_matrix]